The CAS Registry Mumber 5785-48-8 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 5,7,8 and 5 respectively; the second part has 2 digits, 4 and 8 respectively. Calculate Digit Verification of CAS Registry Number 5785-48: (6*5)+(5*7)+(4*8)+(3*5)+(2*4)+(1*8)=128 128 % 10 = 8 So 5785-48-8 is a valid CAS Registry Number.